HyperLogLog: How the Harmonic Mean Estimates Distinct Counts, and What 1.04/√m Assumes
How HyperLogLog, per the 2007 Flajolet et al. paper, estimates distinct counts with register index j and ρ, why it uses a harmonic mean, its range corrections, and what 1.04/√m assumes.
algorithmsdata-structureshyperloglogcardinality-estimation